Results 1 to 3 of 3

Math Help - Prove △ADB ≅ △CDB

  1. #1
    Junior Member
    Joined
    Oct 2010
    From
    New York City
    Posts
    54

    Prove △ADB ≅ △CDB

    Given:

    line segment AB ≅ BC
    line segment BC bisects angle ABC

    Prove: Prove △ADB ≅ △CDB

    I need for someone to show me how to use the statement versus reasons chart.

    See picture attachment.
    Attached Thumbnails Attached Thumbnails Prove △ADB   ≅ △CDB-triangle-abc.jpg  
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,803
    Thanks
    695
    Hello, RTC1996!

    \begin{array}{ccc}\text{Given:} & AB \:=\:BC \\<br />
& BD \text{ bisects }\angle ABC\end{array}

    \text{Prove: }\:\Delta ADB \:\cong\: \Delta CDB


    Code:
                  B
                  *
                 *|*
                * | *
               *  |  *
              *   |   *
             *    |    *
            *     |     *
           *      |      *
        A * * * * * * * * * C
                  D

    \begin{array}{ccccc}<br />
1. & AB \:=\:BC && 1. & \text{ Given} \\<br />
2. & BD\text{ bisects }\angle ABC && 2. & \text{Given} \\<br />
3. & \angle ABD = \angle CBD && 3. & \text{ d{e}f. angle bisector} \\<br />
4. & BD \:=\:BD && 4.&  \text{ Identity postulate} \\<br />
5. & \Delta ADB\:\cong\:\Delta CDB && 5. & \text{ s.a.s.}<br />
\end{array}
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Oct 2010
    From
    New York City
    Posts
    54
    Thank you so much. The problem I have with geometric proofs is not knowing which postulates and theorems to use as the reasons for the statements. I have a list of most postulates and theorems but still cannot work them out. How do you do it? What made you come to the conclusion that triangle ADB is congruent to triangle CDB based on the given information and picture? Also, can you do the other proof which I posted yesterday? It seems that no one wanted to tackle the other geometric proof question. What do we need to know to prove that two triangles are congruent?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. △abc ≅ △dec
    Posted in the Geometry Forum
    Replies: 3
    Last Post: October 6th 2010, 01:30 PM
  2. help me in Prove
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: May 9th 2010, 10:28 AM
  3. In △ABC, prove that-
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: February 2nd 2010, 10:45 AM
  4. Prove this sum tends to zero
    Posted in the Calculus Forum
    Replies: 3
    Last Post: November 13th 2009, 04:39 PM
  5. Replies: 2
    Last Post: August 28th 2009, 02:59 AM

Search Tags


/mathhelpforum @mathhelpforum